The invention relates to a diagnostic x-ray installation for the representation of organs, comprising an x-ray image intensifier television chain, an image memory, and a subtraction device which subtracts the stored and the current video signals, wherein a radiographic control device derives control pulse for the image storage from the EKG of a patient.
In the publication IEEE Catalog No. 76CH1160-1C, 1976, on pages 255 to 260, in the article "Digital Processing of Videoangiocardiographic Image Series Using a Minicomputer", by R. Brennecke et al., a diagnostic x-ray installation of this type is described wherein, synchronously with a given heart phase, several images are integrated and stored in the image memory. Subsequently, an injection of an x-ray contrast medium takes place. The images following the injection are likewise integrated in a heart-phase-synchronous fashion and subtracted from the first stored integration values. The thus-obtained subtraction image is represented on a monitor and shows the organ to be examined, for example, the heart. It has been shown to be disadvantageous in this case that a contrast agent must be injected which burdens the patient. Alsom the organ to be examined is shown at a fixed time. The movement of the heart wall can e.g. not be recognized in this case.